Many compositions, in particular cleaning compositions, contain chelating agents to remove metal compounds from soils and water. A chelating agent serves to seize a metal ion and control it so as to make it difficult for another substance to liberate the metal ion. A commonly known and used chelating agent is ethylenediamine tetraacetic acid (EDTA). Due to the corrosive effect of an aqueous-based cleaner on the metal of a can for storing and dispensing a cleaning composition, the interior metal surface of the can is subjected to passivation so as to shield the surface from the effects of certain materials, such as water. Passivation serves to strengthen and preserve the metal surface by providing a coating of metal and/or metal oxide to the surface to create a shell against corrosion. Nickel and chromium are two known metals used in the passivation of steel cans.
Cleaning compositions further often include components which can be unstable or degrade after an extended period of time, such as one or more dyes. As a further safeguard to aid or increase longevity of the composition stored in the container, the interior surface wall of the container can be lined with a polymer, such as polyethylene terephthalate (PET) or polypropylene (PP).
Applicants have determined, however, that chelating agents can have a detrimental effect on the polymer liner and thereby a detrimental effect on the stability of the composition.